Constipation in Cats: Signs, Causes and When It Becomes an Emergency
A cat that visits the litter box over and over, crouching and straining, is clearly in discomfort. Constipation is common, especially in older cats, and is usually manageable. But it can also signal a serious underlying disease, and some cats strain for a different reason entirely, so careful observation matters.
What constipation looks like
- Straining or crying in the litter box
- Passing small, hard, dry stools, or none
- Frequent trips to the box with little result
- Loss of appetite, vomiting or lethargy
- A tense, uncomfortable belly
- Occasionally, small amounts of liquid stool leaking around a blockage
A cat that strains in the box might also be trying to pee. If a male cat is straining and not producing urine, that is an emergency. See signs of a urinary blockage in cats. Check what is actually coming out, and if you are unsure, call your vet.
Causes
- Dehydration. The colon absorbs water from stool, so a dehydrated cat has hard, dry stool. Chronic kidney disease is a frequent cause. See chronic kidney disease in cats.
- Low fiber or the wrong diet.
- Hairballs and swallowed hair. See hairballs in cats.
- Obesity and inactivity. See how to help an overweight cat lose weight.
- Pain. Arthritis can make it hard to squat. See arthritis in cats.
- Litter box aversion. A dirty or awkward box can make a cat hold stool. See how often to clean a litter box.
- Obstruction. Foreign bodies, tumors, or narrowed pelvis after a fracture.
- Neurological or spinal problems.
- Megacolon. A swollen, weak colon that cannot push stool out, seen more often in middle-aged to older cats.
- Drugs and metabolic disease, such as some medications and hyperthyroidism or electrolyte problems.
When it is an emergency
Call a vet urgently if your cat:
- Has not passed stool in more than 48 hours
- Is vomiting repeatedly
- Has a swollen, painful belly
- Is lethargic, hiding or refusing food
- Strains and cries, with no stool or urine
- Is in obvious pain
See the emergency warning signs guide.
How vets diagnose and treat it
Your vet will examine your cat, feel the belly, check hydration and often take X-rays to see how much stool is in the colon and to look for blockages. Blood and urine tests may check for kidney disease and electrolyte problems.
Treatment may include:
- Fluids to rehydrate
- An enema given by the vet, with the right product and dose
- Manual removal of stool under sedation in severe cases
- Stool softeners, laxatives or medication to improve colon movement
- A high-fiber or prescription diet
- Treatment for underlying disease
Never give a cat a human enema, particularly those containing sodium phosphate, which can be fatal. Do not give mineral oil by mouth.
Megacolon
If constipation becomes repeated, the colon can stretch and lose muscle tone, a condition called megacolon. Cats with megacolon need long-term management, with diet, laxatives, medication and sometimes surgery to remove part of the colon.
What you can do at home
Only for mild cases, and always with vet advice:
- Increase water. Feed wet food, and offer fountains and extra bowls. See how to get a cat to drink more water.
- Add fiber carefully. Some vets suggest a spoonful of plain canned pumpkin. See can cats eat pumpkin.
- Encourage movement. Play daily. See indoor cat enrichment ideas.
- Brush regularly to reduce swallowed fur. See how to brush a cat.
- Keep the litter box clean and accessible, with low sides for older cats. See senior cat care guide.
- Manage weight.
Prevention
Regular checkups, good hydration and a vet-approved diet are the best protection. Watch litter box habits, since changes are often the first sign of trouble.
Constipation in kittens and seniors
Kittens that are constipated may have eaten something they should not, or be dehydrated or have worms. See worms in cats. Seniors are more prone because of arthritis, kidney disease and reduced water intake. In both groups, constipation deserves a prompt vet visit. Never wait for several days.
Tracking litter box habits
Know what is normal for your cat: how many stools a day, their shape and color. A simple note on your phone helps. Changes in size, hardness or frequency are often the first sign of trouble.
When to see a vet
Contact a vet if constipation lasts more than a day or two, recurs or comes with other signs. Use the US vet directory to find a clinic, and see cat vet visit costs.
Frequently asked questions
How long can a cat go without pooping?
Most cats go at least once a day. More than two days without a stool is a reason to call the vet.
Can I give my cat a laxative?
Not without veterinary advice. Some human products are toxic.
Is straining always constipation?
No. A cat straining to pee can look similar, and a blocked male cat is an emergency.
What is megacolon?
A colon that has lost its ability to move stool, usually needing long-term treatment.
Sources and further reading
Health information changes as research does. These organizations publish guidance worth reading alongside our articles.
- American Veterinary Medical Association: pet owner resourcesPolicy-level guidance from the national veterinary association.
- CDC Healthy Pets, Healthy PeoplePublic-health advice on pets, zoonotic disease and safe handling.
- American Animal Hospital AssociationAccreditation body and practice guidelines for companion-animal hospitals.
Tailwisp is independent and written under our editorial policy. Learn who we are, or browse all cat guides.
This article is general educational information, not veterinary advice. Every cat is different. If your cat is unwell, or you are unsure about a symptom, diet change or medication, contact your veterinarian.